Fan governor for thrashing machines



G. T. STRITE. FAN- GOVERNOR FOR THRASHING MACHINES.

APPLlCATION mgr) MAR. 21, 1919.

Patented Feb. 14, 1922.

2 SHEETS-SHEET 1.

nventqr fieoryez'fl g wwm fiz's Fttorneys.

UNITED STATES PATENT OFFICE.

enonen 'r. srnnrn, or MINNEAPOLIS, MINNESOTA, ,ASSIGNOR or ONEHALE cm H. w. BOLENS AND ONE-FOURTH TO CHARLES J. TRAVERS, orne-r ronr w sHINGroN,

WISCONSIN.

FAN GOVERNOR roe THRASHING MAo I s.

Specification of Letterslatent. .Patentecl Feb. 14, 1922.

App1ication filed; March 21, 3:319. Serial No. 284,ll4.

To all whom it may concern:

Be it known that I, GEORGE T. STRITE, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Fan Governors for Thrashing Machines, of which the following is a specification.

My invention relates to fan governors for thrashing machines and an object is to provide means whereby it will be impossible to speed up the fanbeyond a predetermined amount. While my governor or regulating device may be employed in connection with fans used in other relations such as fanning mills, it is intended particularly for use in connection with thrashing machines. In the operation of thrashing machines, when the bundles which are being fed in get past the cylinders the machine immediately speeds up before it is slowed down by succeeding bundles. The resultis that the fan is speeded up to an excessive vdegree and some of the grain is blown overby the strong blast of air which isproduced and escapes with thechaff and straw. The lossof grain in this manner is very considerable and, therefore, an object of my invention is to provide a device which will maintain a constant speed for the fan regardless of the speed at which power to operate the fan is applied. By maintaining a constant speed of the fan the force of the air blast is always at a constant pressure, and by setting the device so thatthe fan shall never exceed a predetermined speedthe waste of grain by blowing over is prevented. Another object of my invention is to construct the governor so that it may be readily adjusted to run the fan at any desired constant speed. This adjustment is desirable, especially for different grains.

The full objects and advantages of my invention will appear in connection with the detailed description, and the novel features embodied in my inventive idea will be particularly pointed out in the claims.

Referring to the accompanying rawings. which illustrate the application of my invention in one for1n,-

Fig. 1 is a side elevational view of a thrashing machine showing the location of the fan to which my invention is applied. Fig. 2 is an end view of my governor. Fig. 3 is an enlarged view mainly in section of my device applied at one end of a fan. Fig. l is "a view in section on the line H of Fig. 2 showing the arrangement of spokes of the brake drum.

Referring to the particular construction shown in the drawings, 10 designates a thrashing maclnne' of usual or desired construction provided with a fan shaft 12 driven in any suitable manner by driving connections operatedby "the same prime mover that operates the rotating cylinders of the machine. Since the fan maybe of any usual construction it is-not considered necessary to illustrate and describe the same in detail and hence only the end thereof to which my device is applied is described. To

the end of the shaft 12 is keyed the hub 1a of' a drum having a rim 16 connected to'the hub by spokes 18, the latterbeing preferably inclined to the plane of rotation of the drum in order to force air through the cusi tomar-y side opening 20 leading into the fan chamber 22. The fan is provided with hubs 24L at each end thereof which are connected by a cylindrical member 26 surrounding but preferably spaced from the shaft 12. the hubs being supported on bushings or bearings 28 interposed between the shaft and-the hubs 24. These hubs are provided with a number of radially-extending angle members 30 to which the supports" 32 forthe fan blades are secured by bolts 34. Apair of arms 36 are pivotally attached to two of the opposite angle members 30 by means of pintles 38. Each of the arms 36 is provided with a block40 of friction material, and these blocks engage the rim 16in the manner of brake shoes. Each of the arms36 at one side of the pintle is provided with a lug. 42, the main portion of the arm extending on the other side of the pintle and terminating in a lug 44:. Bolts 46 pass through holes in the adjacent lugs 42 and 44 and these bolts are provided with springs i8 adjustably held in place between one of the lugs and collars 50 slidable on the bolts; the position of the collars being determined by nuts 52 threaded on the ends-of the bolts.

The operation and advantages of my invention will be apparent from the foregoing description. The fan shaft 12 is connected up so as to be driven normally at a higher speedthan the speed at which it'is desired to drive the fan. The governor is set to drive the fan at a predetermined speed which is considerably less than the normal speed of the fan shaft. The result of this is that not only is it impossible forthe fan to speed up if the speedof the fan shaft exceeds its normal speed, but the speed of the fan shaft may fall considerably belowits normal speed without the speed of the fan tension under which the springs 40 are placed by turning the nuts 52, and when the speed of the fan shaft falls below normal the amount of this slipping becomes less. The governor, therefore, may be set so that the fan shall run at a constant speed which may be varied according to thecharacter ofthe grain which is being put through the machine. 1

In thebperation of my regulating device the fan shaft 12 may be conveniently driven from the cylinder of the thrashing machine by a belt 54 running over a pulley 56 secured to the cylinder shaft and a pulley 58 secured to the fan shaft in the usual manner. As previously stated, the regulating device is set so that thefan is run at a pre determined speed which is considerably less than the normal speed at which I drive the fan shaft. It is obvious that the fan shaft maybe caused to run faster under normal conditions than is customary at present by varying the size of the pulleys over which the belt 54 runs. In connection with the operation of the device, it is to be noted that the friction members attached to the fan operate centrifugally against the tension of the restraining springs. The latter are so set that the centrifugal force will cause the friction" members to move outwardly from the drum and allow slipping as soon'as the fan attains its normal speed, this being considerably less than the normal speed at which the fan shaft is driven. Itis appan ent, therefore, that the speed of the fan shaft may fall to that of the normal speed of the fan without the speed of the fan falling;

I claim:

1. A fan governor for thrashing machines comprising a fan shaft, and means interposed between the said shaft and the fan for driving the latter at a constant speed as the speed of said shaft varies above a predetermined lower limit of speed.

2. A fan governor for thrashing machines comprising a fan shaft, frictional connections between said shaftand the fan, and

means for setting said connections so that they will slip when the fan shaft is running at normal speed. i v

3. A fan governor for thrashing machines comprising a fan "shaft, frictional connections between said shaft and the fan, and means for setting said connections so that they will slip when the fan shaft is running at normal speed and the amount of slipping will decrease asfhe ,speedof the fan shaft falls below normal.

drum, and means for varying the frictional I resistance between said drum and said members;

6. Afan governoi*;for thrashing machines comprising a fan shaft, a friction drum securedto said shaft, arms pivotally attached tothe fan, friction members carried by said arms foicooperation with said drum, springs forholding said members in contact with, said drunnand means for varying the tension ofsaidsprings;

7. A. fan governor for thrashing machines comprising a fan shaft, frictional connec tions betweensaid shaft and the fan, and means forsetting said connections so that they will slip when the fan shaft is running r at normal speed and the amount of slipping will increase. as the'speed of the fan shaft increases abovenorinal.

- 8. A fan governor for thrashing machines comprising a fan shaft, means interposed,

between said shaft and the fan fordriving the latter at a constant speed as the speed of said shaft varies above a predetermined lowerlimit ofspee'd, and means whereby the constant speed maybe varied as desired.

9. A thrashing. machine comprising a cylinder, a fan, means for driving said fan from said cylinder, zrictional connections oetween said fan and the fan shaft, and means'for setting sa d connections so that they will slip the proper amount to maintain the speed of-the fan constant as the speed of the fan shaft and cylinder variesabove a predetermined lower limit of speed.

In testimony whereof I hereunto affix my signatureenonenr. sTnrrn 

